Treating desmoplastic melanoma with immunotherapy before surgery can shrink or eliminate tumors

A new clinical trial is offering hope for patients diagnosed with desmoplastic melanoma, a rare and aggressive form of skin cancer. Researchers have found that treating patients with immunotherapy before surgery can significantly reduce tumor size, and in many cases, eliminate detectable cancer, potentially avoiding more extensive surgical procedures and improving quality of life.

A New Approach to Desmoplastic Melanoma

The findings, published in Nature Cancer, detail a study – SWOG S1512 – conducted by the SWOG Cancer Research Network and funded by the National Cancer Institute. This marks the first study to specifically test neoadjuvant PD-1 blockade, meaning immunotherapy administered before surgery, in patients with this type of melanoma.

Did You Know? Desmoplastic melanoma often grows deep into tissues and sometimes along nerves, making surgical removal particularly challenging.

Researchers focused on 28 patients with surgically removable desmoplastic melanoma. These patients received three infusions of the immunotherapy drug pembrolizumab over nine weeks prior to their scheduled surgery. Tissue samples were collected throughout the process to monitor the tumors’ response to treatment.

Remarkable Results

The results were striking. 71% of patients who received pembrolizumab had no detectable cancer remaining at the time of surgery. Furthermore, side effects associated with the treatment were generally mild. At the three-year follow-up point, 95% of patients were still alive, and 74% showed no signs of cancer recurrence.

Expert Insight: The success of this approach suggests a potential paradigm shift in how desmoplastic melanoma is treated, moving away from reliance on extensive surgery and radiation and toward a more targeted, systemic therapy that offers the possibility of long-term control and improved patient outcomes.

This study builds upon earlier findings from cohort B of SWOG S1512, which demonstrated that pembrolizumab shrank tumors in nearly 90% of patients with advanced, inoperable desmoplastic melanoma.

What Could Happen Next?

If these results continue to hold up in larger studies, pembrolizumab could become a standard pre-surgical treatment for desmoplastic melanoma. Further research may explore optimal dosage and duration of treatment, as well as identify biomarkers that could predict which patients are most likely to benefit from this approach. It is also possible that this strategy could be investigated in combination with other therapies.

Frequently Asked Questions

What is immunotherapy?

Immunotherapy, specifically the drug pembrolizumab used in this study, is a type of cancer treatment that stimulates the body’s own immune system to fight cancer. Pembrolizumab is an anti-PD-1 immune checkpoint inhibitor.

Where does desmoplastic melanoma typically develop?

Desmoplastic melanoma often develops on sun-exposed areas of skin, such as the head and neck.

What was the standard treatment for desmoplastic melanoma before this study?

Historically, the standard approach involved wide surgical excision followed by radiation. Advanced disease was considered largely resistant to systemic therapies like chemotherapy or immunotherapy.

How might advancements in immunotherapy change the outlook for those diagnosed with rare cancers?